Testing System with Mobile Storage Carts and Computer-Controlled Loading Equipment

ABSTRACT

A test system may be provided in which devices under test undergo various types of testing. A first test location may have test equipment for testing input/output devices in the devices under test. A second test location may have test equipment for testing wireless communications circuitry in the devices under test. A mobile storage cart having shelves may be used to store the devices under test and to convey the devices under test between test locations. The storage cart may be configured to engage with a stationary frame structure at a test location. Actuators underneath the storage cart may be used to position the storage cart in a desired location. Distance sensors may be used to obtain status information about each shelf in the storage cart. A computer-controlled loading structure may be used to load the devices under test from the storage cart into test enclosures.

This application claims the benefit of provisional patent applicationNo. 61/595,572, filed Feb. 6, 2012, which is hereby incorporated byreference herein in its entirety.

BACKGROUND

This relates generally to testing systems, and more particularly, totesting systems with computer-controlled loading equipment and mobilestorage carts.

Electronic devices are often tested following assembly to ensure thatdevice performance meets design specifications. An electronic device mayundergo a first type of testing at a first test location and may undergoa second type of testing at a second test location. At each testlocation, a test system operator may load devices under test into aseries of test stations. Following testing at a first test location, theoperator may bring the devices under test to a second location.

The process of manually loading each device under test into each teststation can be cumbersome and burdensome to test system operators. Ifcare is not taken, tests may be less accurate and more time consumingthan desired.

It would therefore be desirable to be able to provide improved ways ofperforming manufacturing operations such as testing operations onelectronic devices.

SUMMARY

A test system may be provided in which devices under test undergodifferent types of testing. A first test location may be used to testinput/output devices in a device under test. A second test location maybe used to test wireless communications circuitry in a device undertest.

Devices under test may be output at a first test location. An operatormay retrieve the devices under test from the output at the first testlocation and may load the devices under test into a device under teststorage cart. Each device under test may be loaded onto a respectiveshelf in the storage cart. The device under test storage cart may beconfigured to hold tens, hundreds, thousands or more of devices undertest. The device under test storage cart may be provided with wheels sothat an operator may easily transport the devices under test from thefirst test location to a second test location.

A second test location may have test equipment for testing wirelesscommunications circuitry. The test equipment at the second test locationmay include one or more electromagnetically shielded test enclosures.The test equipment at the second test location may include one or morecomputer-controlled loading structures. The loading structures mayinclude one or more computer-controlled loading arms that move withrespect to a stationary frame structure.

A stationary frame structure may be provided with registrationstructures. The storage carts may be provided with correspondingalignment structures that are configured to align and mate with theregistration structures at the second test station. One or morecomputer-controlled actuators underneath and coupled to the storage cartmay be used to position the storage cart in a desired location. Byengaging the storage cart with the stationary frame structure at thesecond test station, the computer-controlled loading structure may beable to locate each device under test in the storage cart withpredictable accuracy.

One or more sensors may be used to obtain status information from thestorage cart. The sensors may be distance sensors that are configured toscan and obtain information about each shelf. The sensors may beconfigured to determine whether or not a device is present on a shelfand/or whether or not a device is oriented properly on a shelf.Orientation information can be deduced by using the sensors to determinesurface characteristics of the device under test being scanned.Computer-controlled loading structures may unload storage carts based onthe obtained status information.

One or more computer-controlled loading structures may be used to loaddevices under test from a storage cart into a test enclosure. Acomputer-controlled loading structure may have first and second roboticarms that allow the loading structure to carry more than one deviceunder test at the same time. Following testing, the computer-controlledloading structure may unload the devices under test from the testenclosures and may return the devices under test back to the samestorage cart or may load the devices under test into a different storagecart.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative electronic device suchas a handheld device of the type that may be manufactured usingautomated equipment in accordance with an embodiment of the presentinvention.

FIG. 2 is a schematic diagram of an illustrative electronic device suchas a tablet computer that may be manufactured using automated equipmentin accordance with an embodiment of the present invention.

FIG. 3 is a schematic diagram of an illustrative electronic device withinput/output devices and wireless communications circuitry in accordancewith an embodiment of the present invention.

FIG. 4 is a diagram of an illustrative test system in which a deviceunder test storage cart may be used to convey a plurality of devicesunder test from one test area to another test area in accordance with anembodiment of the present invention.

FIG. 5 is a diagram of manufacturing equipment of the type that may beused in manufacturing an electronic device in accordance with anembodiment of the present invention.

FIG. 6 is a perspective view of an illustrative device under teststorage cart having wheels and registration features in accordance withan embodiment of the present invention.

FIG. 7 is a side view of an illustrative device under test storage cartbeing registered at a computer-controlled loading structure inaccordance with an embodiment of the present invention.

FIG. 8 is a perspective view of a device under test on a slotted shelfin a device under test storage cart in accordance with an embodiment ofthe present invention.

FIG. 9 is a side view of an illustrative device under test storage cartbeing scanned by one or more lasers in accordance with an embodiment ofthe present invention.

FIG. 10 is a graph showing how first and second lasers may be used todetect and obtain the status of a device under test in a storage cart inaccordance with an embodiment of the present invention.

FIG. 11 is a diagram showing how devices under test may be moved betweenstorage carts and test stations by computer-controlled loading equipmentin accordance with an embodiment of the present invention.

FIG. 12 is a perspective view of an illustrative test system in which acomputer-controlled loading structure with two robotic arms may be usedto transport devices under test between storage carts and test stationsin accordance with an embodiment of the present invention.

FIG. 13 is a perspective view of an illustrative test system in which aplurality of computer-controlled loading structures with robotic armsmay be used to transport devices under test between storage carts andtest stations in accordance with an embodiment of the present invention.

FIG. 14 is a flow chart of illustrative steps involved in testingdevices under test using a test system in accordance with an embodimentof the present invention.

DETAILED DESCRIPTION

Electronic devices such as electronic device 10 of FIG. 1 may bemanufactured using automated manufacturing equipment. The automatedmanufacturing equipment may include equipment for assembling devicecomponents together to form an electronic device. The automatedmanufacturing equipment may also include testing systems for evaluatingwhether devices have been properly assembled and are functioningproperly.

Devices such as device 10 of FIG. 1 may be assembled and tested using anautomated manufacturing system. The manufacturing system may include oneor more stations such as one or more test stations for performingtesting operations.

Devices that are being tested in a test system may sometimes be referredto as devices under test (DUTs). Devices under test may be provided tothe test stations using a conveyor belt, using robotic arms, or usingother loading equipment.

Test equipment at each test station may be used to perform an associatedtest on a device. For example, one test station may have equipment fortesting a display in the device. Another test station may have equipmentfor testing an audio component in the device. Yet another test stationmay have equipment for testing light sensors in the device. Yet anothertest station may have equipment for testing wireless communicationscircuitry in the device. Automated equipment in the test system may beused in loading and unloading devices under test, in conveying devicesunder test between test stations, and in performing tests andmaintaining a database of test results.

Any suitable device may be tested using the test equipment. As anexample, device 10 of FIG. 1 may be tested. Device 10 may be a computermonitor with an integrated computer, a desktop computer, a television, anotebook computer, other portable electronic equipment such as acellular telephone, a tablet computer, a media player, a wrist-watchdevice, a pendant device, an earpiece device, other compact portabledevices, or other electronic equipment. In the configuration shown inFIG. 1, device 10 is a handheld electronic device such as a cellulartelephone, media player, navigation system device, or gaming device.

As shown in FIG. 1, device 10 may include a housing such as housing 12.Housing 12, which may sometimes be referred to as a case, may be formedof plastic, glass, ceramics, fiber composites, metal (e.g., stainlesssteel, aluminum, etc.), other suitable materials, or a combination ofthese materials. In some situations, parts of housing 12 may be formedfrom dielectric or other low-conductivity material. In other situations,housing 12 or at least some of the structures that make up housing 12may be formed from metal elements.

Device 10 may, if desired, have a display such as display 14. Display 14may be a touch screen that incorporates capacitive touch electrodes ormay be insensitive to touch. Display 14 may include image pixels formedfrom light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells,electrophoretic display elements, electrowetting display elements,liquid crystal display (LCD) components, or other suitable image pixelstructures. A cover glass layer may cover the surface of display 14.Openings for buttons such as button 20, openings for speaker ports suchas speaker port 22, and other openings may be formed in the cover layerof display 14, if desired.

The central portion of display 14 (i.e., active region 16) may includeactive image pixel structures. The surrounding rectangular ring-shapedinactive region (region 18) may be devoid of active image pixelstructures. If desired, the width of inactive region 18 may be minimized(e.g., to produce a borderless display).

Device 10 may include components such as front-facing camera 24. Camera24 may be oriented to acquire images of a user during operation ofdevice 10. Device 10 may include sensors in portion 26 of inactiveregion 18. These sensors may include, for example, aninfrared-light-based proximity sensor that includes an infrared-lightemitter and a corresponding light detector to emit and detect reflectedlight from nearby objects. The sensors in portion 26 may also include anambient light sensor for detecting the amount of light that is in theambient environment for device 10. Other types of sensors may be used indevice 10 if desired. The example of FIG. 1 is merely illustrative.

Device 10 may include input-output ports such as port 28 and/or port 25.Ports such as port 28 and port 25 may include audio input-output ports,analog input-output ports, digital data input-output ports, or otherports. Each port may have an associated connector. For example, an audioport such as audio port 25 may have an associated four-contact audioconnector, a digital data port may have a connector with two or morepins (contacts), a connector with four or more pins, a connector withthirty pins, or other suitable data port connector.

Sensors such as the sensors associated with region 26 of FIG. 1, camerassuch as camera 24, audio ports such as audio port 25 and speaker port22, buttons such as button 20, and ports such as port 28 may be locatedon any suitable portion of device housing 12 (e.g., a front housing facesuch as a display cover glass portion, a rear housing face such as arear planar housing wall, sidewall structures, etc.). For example,buttons such as button 21 may be located on a sidewall portion ofhousing 12.

FIG. 2 is a perspective view of device 10 in an illustrativeconfiguration in which device 10 is a tablet computer. As shown in FIG.2, device 10 may include a housing such as housing 12. Housing 12 may beformed from metal, plastic, fiber-based composite material, glass,ceramic, other materials, or combinations of these materials. Device 10may have an upper (front) surface that is covered with display 14.Active portion 16 of display 14 may have a rectangular shape (as anexample). Inactive portion 18 of display 14 may have an opening toaccommodate button 20, a window region for camera 24, and a portion suchas portion 26 that is associated with one or more optical sensors suchas an infrared-based proximity sensor and/or an ambient light sensor.Buttons such as button 21 and ports such as audio port 25 may be formedin a sidewall portion of housing 12.

A schematic diagram of an electronic device such as electronic device 10is shown in FIG. 3. As shown in FIG. 3, electronic device 10 may includestorage and processing circuitry 27. Storage and processing circuitry 27may include storage such as hard disk drive storage, nonvolatile memory(e.g., flash memory or other electrically-programmable-read-only memoryconfigured to form a solid state drive), volatile memory (e.g., staticor dynamic random-access-memory), etc. Processing circuitry may be basedon one or more microprocessors, microcontrollers, digital signalprocessors, baseband processors, power management units, audio codecchips, application specific integrated circuits, etc.

Storage and processing circuitry 27 may be used to run software ondevice 10, such as internet browsing applications,voice-over-internet-protocol (VOIP) telephone call applications, emailapplications, media playback applications, operating system functions,etc. To support interactions with external equipment, storage andprocessing circuitry 27 may be used in implementing communicationsprotocols. Communications protocols that may be implemented usingstorage and processing circuitry 27 include internet protocols, wirelesslocal area network (WLAN) protocols (e.g., IEEE 802.11protocols—sometimes referred to as WiFi®), protocols for othershort-range wireless communications links such as the Bluetooth®protocol, cellular telephone protocols, etc.

Circuitry 27 may be configured to implement control algorithms thatcontrol the use of antennas in device 10. For example, to supportantenna diversity schemes and MIMO schemes or beam forming or othermulti-antenna schemes, circuitry 27 may perform signal qualitymonitoring operations, sensor monitoring operations, and other datagathering operations and may, in response to the gathered data, controlwhich antenna structures within device 10 are being used to receive andprocess data. As an example, circuitry 27 may control which of two ormore antennas is being used to receive incoming radio-frequency signals,may control which of two or more antennas is being used to transmitradio-frequency signals, may control the process of routing incomingdata streams over two or more antennas in device 10 in parallel, etc.

Input/output circuitry 29 may be used to allow data to be supplied todevice 10 and to allow data to be provided from device 10 to externaldevices. Input/output circuitry 29 may include input/output devices 31.Input/output devices 31 may include touch screens, displays withouttouch sensor capabilities, buttons, joysticks, click wheels, scrollingwheels, touch pads, key pads, keyboards, microphones, speakers, tonegenerators, vibrators, cameras, sensors, light-emitting diodes and otherstatus indicators, light sources, audio jacks and other audio portcomponents, data ports, light sensors, motion sensors (accelerometers),capacitance sensors, proximity sensors, etc. A user can control theoperation of device 10 by supplying commands through input/outputdevices 31 and may receive status information and other output fromdevice 10 using the output resources of input/output devices 31.

Wireless communications circuitry 33 may include radio-frequency (RF)transceiver circuitry formed from one or more integrated circuits, poweramplifier circuitry, low-noise input amplifiers, passive RF components,one or more antennas, transmission lines, and other circuitry forhandling RF wireless signals. Wireless signals can also be sent usinglight (e.g., using infrared communications).

Wireless communications circuitry 33 may include satellite navigationsystem receiver circuitry 35, transceiver circuitry such as transceivercircuitry 37 and 39, and antenna circuitry such as antenna circuitry 41.Satellite navigation system receiver circuitry 35 may be used to supportsatellite navigation services such as United States' Global PositioningSystem (GPS) (e.g., for receiving satellite positioning signals at 1575MHz) and/or other satellite navigation systems.

Transceiver circuitry 37 may handle 2.4 GHz and 5 GHz bands for WiFi®(IEEE 802.11) communications and may handle the 2.4 Bluetooth®communications band. Circuitry 37 may sometimes be referred to aswireless local area network (WLAN) transceiver circuitry (to supportWiFi® communications) and Bluetooth® transceiver circuitry. Circuitry 33may use cellular telephone transceiver circuitry (sometimes referred toas cellular radio) 39 for handling wireless communications in cellulartelephone bands such as bands at 850 MHz, 900 MHz, 1800 MHz, 1900 MHz,and 2100 MHz or other cellular telephone bands of interest.

Examples of cellular telephone standards that may be supported bywireless circuitry 33 and device 10 include: the Global System forMobile Communications (GSM) “2G” cellular telephone standard, theEvolution-Data Optimized (EVDO) cellular telephone standard, the “3G”Universal Mobile Telecommunications System (UMTS) cellular telephonestandard, the “3G” Code Division Multiple Access 2000 (CDMA 2000)cellular telephone standard, and the “4G” Long Term Evolution (LTE)cellular telephone standard. Other cellular telephone standards may beused if desired. These cellular telephone standards are merelyillustrative.

Wireless communications circuitry 33 may include circuitry for othershort-range and long-range wireless links if desired. For example,wireless communications circuitry 33 may include wireless circuitry forreceiving radio and television signals, paging circuits, etc. In WiFi®and Bluetooth® links and other short-range wireless links, wirelesssignals are typically used to convey data over tens of hundreds of feet.In cellular telephone links and other long-range links, wireless signalsare typically used to convey data over thousands of feet or miles.

Wireless communications circuitry 33 may include one or more antennas41. Antennas 41 may be formed using any suitable antenna type. Forexample, antennas 41 may include antennas with resonating elements thatare formed from loop antenna structures, patch antenna structures,inverted-F antenna structures, slot antenna structures, planarinverted-F antenna structures, helical antenna structures, hybrids ofthese designs, etc. Different types of antennas may be used fordifferent bands and combinations of bands. For example, one type ofantenna may be used in forming a local wireless link antenna and anothertype of antenna may be used in forming a remote wireless link antenna.

FIG. 4 is a diagram of an illustrative system of the type that may beused for manufacturing operations such as device testing. As shown inFIG. 4, system 48 may include one or more test areas such as test area50 and test area 52. During testing operations, many devices (e.g.,tens, hundreds, thousands or more of devices 10) may be tested in a testsystem such as test system 48. Test system 48 may include testaccessories, computers, network equipment, tester control boxes,cabling, test enclosures, and other test equipment for gathering testresults.

Test areas 50 and 52 may include different types of test equipment forperforming one or more tests on a device under test such as device 10.For example, test area (e.g., test area A) may include test equipmentfor performing one or more tests on input/output devices 31 (FIG. 3) ofdevice under test 10. Input/output devices that may be tested at testarea A include sensors in device 10 (e.g., ambient light sensors,proximity sensors, touch sensors, etc.), cameras in device 10 (e.g.,front camera, rear camera, etc.), buttons in device 10, otherinput/output devices 31 in device 10, etc.

Test area 52 (e.g., test area B) may include test equipment forperforming one or more tests on wireless communications circuitry 33(FIG. 3) in device 10. For example, test area B may include over-the-airtest equipment such as test equipment for generating radio-frequencytest signals and for performing radio-frequency measurements on signalsreceived from device under test 10.

If desired, a manufacturing facility may include test areas forperforming other types of tests. For example, system 48 may include atest area for performing longer-duration testing (e.g., tests that maytake one or more hours such as battery testing, extreme temperaturetesting, etc.). Any number of suitable test areas may be included insystem 48. The example of FIG. 4 in which system 48 includes test area Aand test area B is merely illustrative.

During manufacturing operations, a device under test may undergo a firsttype of testing at a first test area (e.g., test area A) and may then bemoved to a second test area (e.g., test area B) to undergo a second typeof testing. Devices under test may be conveyed between test areas usingmoveable storage equipment such as device under test storage cart 340.Storage carts 340 may be, for example, mobile shelves that can be movedbetween different pieces of equipment during manufacturing. Carts 340may be configured to store tens, hundreds, thousands or more of devicesunder test.

Carts 340 may serve as input and output storage locations for devicesunder test. Carts 340 may be loaded and unloaded by an operator, may beloaded and unloaded by computer-controlled loading equipment (e.g., oneor more computer-controlled robotic arms), or may be loaded and unloadedby a combination of operators and computer-controlled loading equipment.

For example, consider a scenario in which a plurality of devices undertest have completed testing at test area A and are ready to be tested attest area B. An operator may load devices under test from the output oftest area A to storage cart 340. The storage cart may then be moved totest area B by the operator so that the devices under test may be testedat test area B.

FIG. 5 is a diagram of an illustrative system of the type that may beused for manufacturing operations such as device testing. System 30 may,for example, be used in test areas such as test area A of FIG. 4. Asshown in FIG. 5, system 30 may include one or more stations such as teststations 36. Each test station may include test equipment for performingone or more tests on device under test 10.

Device under test 10 may, if desired, be installed in a test tray suchas tray 32. Tray 32 may be configured to receive one or more devicesunder test. For example, tray 32 may have multiple slots, each of whichis configured to receive a corresponding device under test. If desired,tray 32 may be configured to receive only a single device under test.

Device 10 may be installed in test tray 32 manually or using automatedequipment. To facilitate manual installation, test tray 32 may includefeatures to facilitate human manipulation. For example, test tray 32 mayinclude features that help an operator open and close clamps or otherdevice holding features in test tray 32.

Each test station 36 may include a portion that is configured to receivea device under test. As shown in FIG. 3, for example, each test station36 may be provided with test fixture 34. Test fixtures 34 may beconfigured to receive device under test 10 directly or, as shown in FIG.3, may each be configured to receive device under test 10 after deviceunder test 10 has been mounted in test tray 32. With this type ofarrangement, test tray 32 may serve as an interface between device undertest 10 and test fixtures 34. Test tray 32 may, for example, be morerobust than device 10, may have engagement features that are configuredto mate with test system loading equipment, may have an identificationnumber that facilitates tracking, and may have other features thatfacilitate testing of device under test 10 by test stations 36.

Device under test 10 and test tray 32 may be conveyed between teststations 36 using a conveyor belt such as conveyor belt 38 (e.g., a beltthat moves in direction 44). When using a conveyor system such as one ormore conveyor belts 38, each test station 36 may be provided withloading mechanisms and/or positioners such as test tray loaders 72. Testtray loaders 72 may be located at one or more intermediate positionsalong a line of test stations 36. Test tray loaders 72 may include oneor more computer-controlled positioning arms. Loaders 72 may be used inpicking up a test tray and device under test from conveyor 38, may beused to present the tray and device to test equipment at the teststation for testing of the device, and may be used to replace the testtray and device under test on conveyor 38 following testing. If desired,loaders 72 may also be configured to pass devices and trays directlybetween test stations 36.

Test stations 36 may provide test results to computing equipment such astest host 42 (e.g., one or more networked computers) for processing.Test host 42 may maintain a database of test results, may be used insending test commands to test stations, may track individual trays anddevices under test as the trays and devices pass through system 30, andmay perform other control operations.

Following testing at test area A, an operator may pick up devices undertest at the end of conveyor 38. The devices under test that areretrieved from the end of conveyor 38 may, as an example, be placed in astorage cart such as storage cart 340 of FIG. 6 or may be fed intoadditional systems. If desired, the operator may remove device undertest 10 from tray 32 before loading device under test 10 into cart 340.

If desired, storage cart 340 may be used to convey the devices undertest between different portions of a manufacturing facility (e.g.,between test area A and test area B of FIG. 4). As shown in FIG. 6, cart340 may have shelves 342 on which devices under test 10 may be stored.Wheels 344 may be provided to allow cart 340 be moved between testareas. For example, after loading a cart with devices under test fromthe output of test area A, an operator may roll the cart to test area B.

Storage cart 340 may be provided with registration and alignmentfeatures such as balls 346 that allow cart 340 to engage with testequipment at a test area such as test area B of FIG. 4. The registrationand alignment features may be used to locate a device under test in thestorage cart with predictable accuracy with respect to athree-dimensional positionable frame. The cart may be retained withinthe frame under computer control. The loading and unloading of thedevices under test form the cart may also be computer-controlled (e.g.,to ensure that no devices under test are loaded or unloaded unless thecart is in a desired location).

FIG. 7 is a side view of cart 340 showing how cart 340 may engage withtest equipment at a test area. As shown in FIG. 7, a test area may beprovided with an assembly of computer-controlled loading structures suchas computer-controlled loading structure 42. Computer-controlled loadingstructure 42 may include stationary frame structures such as stationaryframe structures 360. Stationary frame structures 360 may be attached tomanufacturing facility floor 354 or other support structures. Loadingstructure 42 may include a computer-controlled positioner such aspositioner 356 that may be used to position a loading arm such asloading arm 358 along three axes (X, Y, and Z). Loading arm 358 may movewith respect to stationary frame structures 360. Arm 358 may be used toload devices under test 10 onto shelves 342 and may be used to unloadtest devices under test 10 from shelves 342.

To ensure accurate placement of loading arm 358 as it loads and unloadsdevices under test 10 from storage cart 340, storage cart 340 may beprovided with registration and alignment features that engage withcorresponding registration and alignment features associated withloading structure 42. For example, registration features such as balls346 may be formed on portions of cart 340. In the example of FIG. 7,balls 346 have been mounted on upper surface 345 of cart 340. Balls 346may be used to register the location of cart 340 relative to loadingstructure 42 (e.g., relative to frame structures 360). Loading structure42 may have corresponding registration and alignment features such asregistration structures 350. Registration structures 350 may be mountedto frame structures 360. Registration structures 350 may have notches orother features that are configured to receive corresponding registrationfeatures on cart 340 such as balls 346.

Cart 340 may be mounted on air-controlled (or motor-controlled)actuators such as actuators 352 and/or 353. Actuators 352 may be mountedon wheels 344. Actuators 353 may be mounted in a fixed location on floor354. When it is desired to register the position of cart 340 relative toloading structure 42, an operator may roll cart 340 into a position inwhich balls 346 are aligned with registration structures 350 and inwhich cart 340 overlaps a floor-mounted actuator such as actuator 353.Actuators 352 may be used to lock wheels 344 in place to prevent cart340 from moving during testing. Actuators 352 and/or 353 may also beused to drive balls 346 upwards into registration structures 350,thereby aligning cart 340 relative to load structure 42 (e.g., relativeto frame structures 360). During alignment operations, the shapes andlocations of registration structures 350 and balls 346 cooperate toensure that cart 340 is placed in its desired location. After cart 340and therefore shelves 342 of cart 340 have been placed in a knownlocation relative to loading structure 42 in this way, loading structure42 may use arm 358 to load and/or unload devices under test 10 fromstorage cart 340.

When registration balls 346 and registration structures 350 are engaged,an electrical connection may be formed between cart 340 and loadingstructure 42. This may allow storage cart 340 to communicate with a testhost such as test host 40. For example, information about storage cart340 may be conveyed to test host 40 via registration balls 346,registration structure 350, frame structure 360, and path 351.Information that may be conveyed to test host 40 includes the number ofdevices under test stored in cart 340, which shelves contain a deviceunder test 10, which shelves contain a properly oriented device undertest 10, other information about cart 340, etc. This type of informationmay be used when loading and unloading storage cart 340.

If desired, arm 358 may be provided with vacuum or suction features suchas pneumatic structures 370 that may be used to temporarily adheredevice 10 to arm 358. Pneumatic features 370 may be computer-controlledand may be selectively enabled and disabled by a test system operator.This may allow arm 358 to move swiftly between storage carts and teststations without device 10 sliding off arm 358.

If desired, device under test 10 may rest upon on one or more raisedmounting structures on shelf 342 such as mounting structures 55.Mounting structures 55 may produce a gap 57 between device 10 and shelf342. Gap 57 may allow for arm 358 to pick up and drop off device 10 atshelf 342. For example, arm 358 may have a spatula-like shape that maybe inserted into gap 57 to lift device 10 from mounting structures 55and to place device 10 on mounting structures 55. As another example,each shelf 342 may have a slot such as slot 362 of FIG. 8. Slots 362 mayallow arm 358 to pick up and drop off device 10 at shelf 342.

If desired, status information may be obtained from storage cart 340 byperforming a status scan on cart 340. FIG. 9 is a diagram of anillustrative system that may be used to scan and obtain statusinformation from storage cart 340. As shown in FIG. 9, one or morelasers such as lasers 400 may be used to scan each shelf 342 in storagecart 340. Lasers 400 may be, for example, distance sensors which uselaser beams to determine the distance to an object. This is, however,merely illustrative. Any suitable type of laser may be used to scanshelves 342 to obtain status information from storage cart 340 (e.g.,ultrasound lasers, other types of lasers, etc.).

Lasers 400 may perform a status scan of each shelf 342 in cart 340 toobtain status information about each shelf 342. Obtaining statusinformation about a shelf may include, for example, determining whetheror not a device is present on the shelf, determining whether or not adevice is oriented properly on the shelf, and/or determining otherinformation about the device on the shelf. Based on the data obtainedfrom lasers 400, a status may be assigned to each scanned shelf. Forexample, a shelf on which device 10 is not present (e.g., shelf 404) maybe assigned a status of “EMPTY.” A shelf on which device 10 is presentbut is oriented improperly (e.g., shelf 406 and shelf 418) may beassigned a status of “NG” to indicate that the status of that shelf is“Not Good.” A shelf on which device 10 is present and is orientedproperly (e.g., shelf 408) may be assigned a status of “OK” to indicatethat the status of that shelf is acceptable.

Status information obtained by lasers 400 may be conveyed locally ateach shelf (e.g., via a status indicator located at each shelf) and/ormay be conveyed to a computer in the manufacturing facility. Forexample, status information may be conveyed to a computer that controlsloading structure 42 (FIG. 7). Loading structure 42 may load and unloadstorage cart 340 based on the obtained status information. For example,loading structure 42 may only pick up devices 10 from cart 340 that areoriented properly (e.g., devices 10 on shelves 342 that have beenassigned a status of “OK”). Scanning cart 340 in this way may ensurethat devices 10 are not improperly placed in a test chamber or test cellafter being unloaded from storage cart 340 by loading structure 42.

As shown in FIG. 9, lasers 400 may perform a status scan by moving alonga column of shelves 342 (e.g., in direction 412). If desired, lasers 400may move in unison. Lasers 400 may direct laser beams into each shelf342. As the lasers move along a column of shelves 342, each laser maymeasure the distance traveled by the laser beam before it is reflectedby an object or surface. Thus, when lasers 400 scan a shelf 342 wheredevice 10 is present, the laser beams will be reflected at device 10 andlasers 400 will both register a decrease in distance between the laserand the point of reflection. When lasers 400 scan a shelf 342 wheredevice 10 is not present, the laser beams will instead be reflected at aback wall of shelf 342. In the example of FIG. 9, lasers may beconfigured to scan column-by-column until the storage cart status scanis complete. This is, however, merely illustrative. If desired, lasers400 may be configured to scan row-by-row or may be configured to scancell-by-cell in any desired order.

In order to obtain the orientation status of device 10 in storage cart340 (e.g., in order to determine whether or not device 10 is properlyoriented), each laser may determine surface characteristics of theoutward facing surface of device 10 on shelf 342. For example, a buttonon device 10 such as button 21 may have a slightly raised surfacerelative to the surface of the housing of device 10. As another example,a port such as audio port 25 and/or data port 28 may be formed as anopening in the housing of device 10. Surface characteristics of thistype (e.g., protrusions, recesses, gaps, buttons, holes, etc.) may bedistinguishable using lasers 400. Hence, a properly oriented device onshelf 342 may be defined by the surface characteristics of theoutward-facing surface of device 10 when it is properly oriented onshelf 342.

For example, a properly oriented device may be defined by having audioport 25 on side 414 of the shelf, facing outward, and by having button21 on side 416 of the shelf, facing outward. An improperly orienteddevice may then be defined by either having data port 28 facing outward(as shown in shelf 418, for example) or having button 21 on side 414 andport 25 on side 416 (as shown in shelf 406, for example).

This definition is merely an illustrative example of how one mightdefine “properly oriented.” For a shelf to be assigned a status of “OK,”Laser 1 would need to register the surface characteristics of audio port25 (e.g., an opening in the housing of device 10) and Laser 2 would needto register the surface characteristics of button 21 in device 10 (e.g.,a raised surface on the housing of device 10).

FIG. 10 is a set of graphs showing examples of data that might berecorded by Laser 1 and Laser 2 during a scan of a particular shelf(e.g., shelf 408 of FIG. 9). The upper graph is representative of thedistance D measured by Laser 1 as a function of time t and the lowergraph is representative of the distance D measured by Laser 2 as afunction of time t.

From time t₀ to time t₁, the laser beam is being reflected at the backwall of shelf 408. At time t₁, each laser registers a decrease indistance between the laser and the point of reflection, therebyindicating the presence of device 10. Between time t₁ and time t₂, eachlaser registers a unique surface characteristic of device 10 as thelasers move across the surface of device 10. Laser 1 registers a slightincrease in measured distance, indicating that the laser beam may haveencountered an opening in the housing of device 10 (e.g., indicating thepresence of audio port 25). Laser 2 registers a slight decrease inmeasured distance, indicating that the laser beam may have encountered araised surface on the housing of device 10 (e.g., indicating thepresence of button 21). At time t₂, both lasers register an increase indistance as the lasers move past device 10 and onto the next shelf inthe column of shelves 342.

Each unique orientation of device 10 on shelf 342 may be identified witha distinct set of measurements from lasers 400. In this way, eachorientation can be characterized as being acceptable or unacceptable (ifdesired). In the example described in connection with FIG. 9, being“properly oriented” on a shelf is defined as having audio port on side414 of the shelf and button 21 on side 416 of the shelf, facing outward(e.g., the orientation shown in shelf 408). This is, however, merelyillustrative. In general, any orientation of device 10 on shelf 342 maybe defined as “properly oriented.” For example, if desired, “properlyoriented” may be defined as having data port 28 facing outward (as shownon shelf 418 of FIG. 9) or may be defined as having button 21 on side414 and audio port 25 on side 416 (as shown on shelf 406 of FIG. 9). Anyorientation of device 10 on shelf 342 may be identified using lasers400.

If desired, storage carts 340 may serve as input and output storagelocations for devices under test 10. Consider, as an example, testsystem 30 of FIG. 11. As shown in FIG. 11, test system 30 may includedevice under test storage equipment such as carts 340. Carts 340 mayserve as input storage locations for devices under test 10 that are“waiting” to be tested at a given test station. Carts 340 may also serveas output storage locations for devices under test 10 that have alreadybeen tested at a given test station. For example, the leftmost cart 340in FIG. 11 may serve as an input storage location for devices under test10 that are waiting to be tested in test station cell (group) C1; themiddle cart 340 may serve as an output storage location for devicesunder test 10 that have been tested in test station cell (group) C1 andas an input storage location for devices under test 10 that are waitingto be tested in cell C2 of test stations 36; and the rightmost cart 340may serve as an output storage location for devices under test 10 thathave been tested by the test stations in test station cell C2.

Loading structures 42 may have one or more computer-controlled arms thatmay be positioned along three axes. Loading structures 42 may beconfigured to span multiple carts 340 and/or multiple test stations 36.For example, the leftmost loading structure 42 of FIG. 11 may beconfigured to handle devices under test for the leftmost cart 340, thetest stations in test station cell C1, and the center cart 340. Therightmost loading structure 42 of FIG. 11 may be configured to handledevices under test for the center cart, the test stations in teststation cell C2, and the rightmost cart.

During operation, the leftmost loading structure 42 may retrieve devicesunder test from the leftmost cart 340, may test these devices under testusing one or more test stations 36 in cell C1, and, following testing,may place the devices under test in the middle cart 340. After centercart 340 is loaded with devices under test 10, center cart 340 may, ifdesired, be moved to a new location for unloading (e.g., by rolling thecart on wheels). In configurations of the type shown in FIG. 11 in whichthe center cart falls within the reach of the loading structures foradjacent cells, the center cart may serve as an output/input interfaceand need not be moved before being unloaded. Following testing in cellC2, the rightmost loading structure of FIG. 11 may move the testeddevices under test 10 from the test stations of cell C2 to the rightmostcart 340 in the system.

FIG. 12 is a perspective view of an illustrative test system such astest system 500 showing another example of how storage carts, teststations, and computer-controlled loading structures may interact witheach other. As shown in FIG. 12, loading structure 42 may be providedwith multiple robotic loading arms such as robotic arms 358A and 358B.Loading structure 42 may be used to load and unload storage carts suchas storage carts 340A and 340B and to load and unload test stations suchas test station 36.

Test station 36 may include one or more test cells such as test cells502. All of test cells 502 at test station 36 may be used to perform thesame type of test or, if desired, different test cells 502 may be usedto perform different types of tests. For example, a first column 36A oftest cells 502 may be used to perform a first type of test, and a secondcolumn 36B of test cells 502 may be used to perform a second type oftest. For simplicity, only six test cells are shown in FIG. 12. However,there may be tens, hundreds, thousands or more of test cells 502 at agiven test station, if desired.

If desired, storage carts 340A and 340B may be located on both sides oftest station 36. In some configurations, the storage carts may each beused as input and output storage locations for devices under test 10.For example, loading structure 42 may load devices under test 10 fromstorage cart 340A into test station 36 for testing. Following testing,loading structure 42 may unload devices under test 10 from test station36 and return the devices to storage cart 340A. Following testing of alldevices 10 from storage cart 340A, loading structure 42 may then startloading devices 10 from storage cart 340B into test station 36.Following testing, loading structure 42 may unload devices under test 10from test station 36 and return the devices to storage cart 340B.

In other configurations, a first storage cart may be used as an inputstorage location for devices under test 10, and a second storage cartmay be used as an output storage location for devices under test 10. Forexample, loading structure 42 may load devices 10 from storage cart 340Ainto test station 36 for testing. Following testing, loading structure42 may unload devices 10 from test station 36 and may bring the devicesto storage cart 340B.

Loading structure 42 may be configured to carry more than one deviceunder test at the same time. For example, robotic arm 358A may carry afirst device under test while robotic arm 358B carries a second deviceunder test. Loading structure 42 may be configured to move back andforth in the x-direction along frame structure 360, and robotic arms358A and 358B may be configured to move along three different axes(e.g., along orthogonal axes X, Y, and Z).

Providing a single loading structure 42 with multiple arms 358 mayincrease the efficiency of system 500 by allowing a single loadingstructure 42 to perform the functions of multiple loading structures 42.

In order to describe how a computer-controlled loading structure of thetype shown in FIG. 12 might operate in system 500, consider a simplifiedscenario in which two devices, DUT 1 and DUT 2, are each waiting to betested at test station 36A and test station 36B. Loading structure 42may use arm 358A to pick up DUT 1 from storage cart 340A and to placeDUT 1 into test cell 502A (e.g., a test cell at test station 36A).Loading structure 42 may then use arm 358A may to pick up DUT 2 fromstorage cart 340A. With DUT 2 in arm 358A, loading structure 42 may movetowards test cell 502A. Once at test cell 502A, loading structure 42 mayuse free arm 358B to remove DUT 1 from test cell A. Following removal ofDUT 1 from test cell 502A, loading structure 42 may use arm 358A toplace DUT 2 into test cell 502A. Loading structure 42 may then movetowards test cell 502B and may use arm 358B to place DUT 1 into testcell 502B (e.g., a test cell at test station 36B). Loading structure maythen move back to test cell 502A and may use arm 358A to remove DUT 2from test cell 502A. Loading structure 42 may then move towards testcell 502B. Using arm 358B, loading structure 42 may remove DUT 1 fromtest cell 502B. Following removal of DUT 1 from test cell 502B, loadingstructure 42 may use arm 358A to place DUT 2 into test cell 502B.Loading structure 42 may then move towards storage cart 340A and may usearm 358B to place DUT 1 back into storage cart 340A. Loading structure42 may then move towards test cell 502B and may use either arm to removeDUT 2 from test cell 502B and to return DUT 2 back to storage cart 340A.Assuming (for simplicity) that DUT 2 was the last device to be tested instorage cart 340A, loading structure 42 may move to storage cart 340B totest devices in storage cart 340B at test stations 36A and 36B (e.g.,using a similar method as the one just described).

By providing loading structure 42 with multiple arms, loading structure42 may “switch” devices in a test cell without moving away from thattest cell. For example, loading structure 42 may remove a first devicefrom a test cell with a first arm while holding a second device in asecond arm. After removing the first device from the test cell, loadingstructure 42 may use the second arm to place the second device in thetest cell. This may eliminate the need to return to a storage cart inorder to replace a first device in a test cell with a second device.

FIG. 13 is a perspective view of an illustrative test system such astest system 600 showing yet another example of how storage carts, teststations, and computer-controlled loading structures may interact witheach other. As shown in FIG. 13, there may be a plurality of loadingstructures such as loading structure 42A and loading structure 42Boperating in test system 600. Each loading structure may be providedwith one or more robotic arms such as robotic arms 358A and robotic arm358B. Loading structures 42A and 42B may be used to load and unloadstorage carts 340A and 340B and to load and unload test station 36.

Loading structures 42A and 42B may be configured to move independentlyof one another. Loading structures 42A and 42B may each move back andforth in the x-direction along frame structures 360, and robotic arms358A and 358B may each be configured to move in three dimensions (X, Y,and Z). In the illustrative example of FIG. 12, loading structures 42share common frame structures (e.g., frame structures 360). This is,however, merely illustrative. If desired, loading structures 42 may beprovided with separate frame structures.

In some configurations, each storage cart may be used as both an inputand an output storage location for devices 10. In this type ofconfiguration, devices under test 10 may unloaded from a storage cartfor testing and, following testing, may be returned to the storage cart.

In other configurations, a first storage cart such as storage cart 340Amay serve as an input storage location for devices under test 10 and asecond storage cart such as storage cart 340B may serve as an outputstorage location for devices under test 10.

If desired, loading structures 42A and 42B may each perform uniquefunctions and/or may operate independently of one another. For example,loading structure 42A may use arm 358A to load devices from storage cart340A into test station 36. Meanwhile, loading structure 42B may use arm358B to load devices from test station 36 to storage cart 340B.

Following testing at a test station, devices under test 10 may providean audible or visual status indicator to indicate whether or not thetest was successful (e.g., whether or not the device “passed” or“failed”). For example, if performance of device 10 is found to besatisfactory during testing, a device may display a green screen toindicate that the device has “passed” that particular test. Ifperformance of device 10 is found to be unsatisfactory, device 10 maydisplay a red screen to indicate that the device has “failed” thatparticular test and may need to be reworked, retested, or discarded.

The examples described in connection with FIGS. 10-12 are merelyillustrative examples that are meant to shed light on how a test systemthat includes storage carts, test stations, and computer-controlledloading equipment might operate. In general, any suitable combination ofloading and unloading methods may be used. The mobility of storage carts340 and the programmability of loading structures 42 allow for amanufacturing facility to customize its test systems as desired.

FIG. 13 is a flow chart of illustrative steps involved in testingdevices at multiple test areas such as test area A and test area B (FIG.4).

At step 702, an operator may retrieve device under test 10 from theoutput of test area A. The output of test area A may be, for example,the end of a conveyor belt such as conveyor belt 38 of FIG. 5.

At step 704, an operator may load device under test 10 into a storagecart such as storage cart 340 (FIG. 6). If device under test 10 is toundergo over-the-air testing (e.g., testing of wireless communicationscircuitry), it may be desirable to remove device under test 10 from testtray 32 (if needed) prior to loading device under test 10 into storagecart 340.

At step 706, an operator may roll storage cart 340 to a differentportion of the manufacturing facility such as test area B. Storage cart340 may be moved from test area A to test area B when it has reached adesired capacity of devices under test 10 from the output of test areaA.

At step 708, an operator may align the registration features on cart 340with corresponding registration features at test area B to register cart340 at test area B. Once aligned, actuators such as actuators 352 and353 (FIG. 7) may drive cart 340 upwards to place cart 340 in a desiredlocation. This may allow computer-controlled loading arms to locateindividual devices under test in cart 340 with predictable accuracy.

At step 710, one or more lasers may be used to perform a storage cartstatus scan. The storage cart status scan may assess which shelves areempty, which shelves contain a device under test, which shelves have aproperly oriented device, and which shelves have an improperly orienteddevice. The status of each shelf may be conveyed locally at each shelfand/or may be conveyed to a computer that controls loading structure 42.

At step 712, one or more loading structures 42 may use one or morerobotic arms 358 to pick up devices from cart 340 and to place thedevices into test cells at test area B. If desired, the loadingstructure may pick up devices from cart 340 based on the statusinformation obtained in step 712.

At step 714, devices under test 10 are tested in the test cells at testarea B. Any suitable type of test may be performed at test area B. Forexample, test area B may be used to perform over-the-air testing ofwireless communications circuitry 33 (FIG. 3) in devices under test 10.

At step 716, one or more loading structures 42 may use one or morerobotic arms 358 to remove devices under test 10 from the test cells.The tested devices may be returned to the storage cart that they wereunloaded from originally, or the tested devices may be loaded into adifferent storage cart.

The foregoing is merely illustrative of the principles of this inventionand various modifications can be made by those skilled in the artwithout departing from the scope and spirit of the invention. Theforegoing embodiments may be implemented individually or in anycombination.

What is claimed is:
 1. A test system for testing a plurality of devicesunder test, comprising: a device under test storage cart configured tostore the plurality of devices under test; a test station for testingthe plurality of devices under test; and a computer-controlled loadingstructure configured to move a device under test in the plurality ofdevices under test from the device under test storage cart to the teststation.
 2. The test system defined in claim 1 wherein the device undertest storage cart comprises a plurality of shelves and wherein eachshelf in the plurality of shelves is configured to store an associateddevice under test in the plurality of devices under test.
 3. The testsystem defined in claim 1 wherein the computer-controlled loadingstructure comprises at least one robotic arm configured to move alongthree different axes.
 4. The test system defined in claim 3 wherein theat least one robotic arm comprises pneumatic structures that areconfigured to temporarily adhere the device under test to the roboticarm.
 5. The test system defined in claim 1, further comprising: at leastone sensor configured to scan and to obtain status information from thedevice under test storage cart, wherein the computer-controlled loadingstructure is further configured to unload the device under test storagecart based on the obtained status information.
 6. The test systemdefined in claim 5 wherein the at least one sensor comprises at leastone distance sensor.
 7. The test system defined in claim 5 wherein thestatus information comprises information about the orientation of eachof the devices under test in the device under test storage cart.
 8. Thetest system defined in claim 1 wherein the computer-controlled loadingstructure is coupled to a stationary frame structure and is configuredto move with respect to the stationary frame structure, wherein thestationary frame structure comprises registration structures, andwherein the device under test storage cart comprises alignment featuresconfigured to align and mate with the registration structures.
 9. Amethod of using a test system to test a plurality of devices under test,wherein the test system includes a device under test storage cart, atest enclosure, and a computer-controlled loader coupled to a stationaryframe structure, the method comprising: loading the plurality of devicesunder test into the device under test storage cart; engaging the deviceunder test storage cart with the stationary frame structure; with atleast one sensor, obtaining status information about the plurality ofdevices under test in the device under test storage cart; and inresponse to obtaining the status information and while the device undertest storage cart is engaged with the stationary frame structure,loading at least some of the plurality of devices under test from thedevice under test storage cart into the test enclosure with thecomputer-controlled loader.
 10. The method defined in claim 9 whereinengaging the device under test storage cart with the stationary framestructure at the test area comprises aligning alignment features on thedevice under test storage cart with corresponding registrationstructures on the stationary frame structure.
 11. The method defined inclaim 9 wherein the at least one sensor comprises at least one laser andwherein obtaining status information about the devices under testcomprises using the at least one laser to determine surfacecharacteristics of the devices under test.
 12. The method defined inclaim 9 wherein the device under test storage cart comprises a pluralityof shelves and wherein obtaining status information about the devicesunder test comprises using the at least one sensor to determine whetheror not a device is present on a shelf in the plurality of shelves. 13.The method defined in claim 9 wherein the device under test storage cartcomprise a plurality of shelves and wherein obtaining status informationabout the devices under test comprises using the at least one sensor todetermine whether or not a device is oriented properly on a shelf in theplurality of the shelves.
 14. The method defined in claim 9 wherein thecomputer-controlled loader comprises first and second robotic arms andwherein loading at least some of the devices under test from the deviceunder test storage cart into the test enclosure comprises: with thefirst robotic arm, picking up a first device under test in the pluralityof devices under test from the device under test storage cart; with thefirst robotic arm, placing the first device under test into a testenclosure; with a second robotic arm, picking up a second device undertest in the plurality of devices under test from the device under teststorage cart; while holding the second device under test with the secondrobotic arm, removing the first device under test from the testenclosure with the first robotic arm; and while holding the first deviceunder test with the first robotic arm, placing the second device undertest into the test enclosure.
 15. A method of testing a plurality ofdevices under test, comprising: testing the plurality of devices undertest using a first set of test stations; following testing of theplurality of devices under test with the first set of test stations,loading the plurality of devices under test into a device under teststorage cart; moving the device under test storage cart to a newlocation; and with at least one computer-controlled robotic arm, loadinga device under test in the plurality of devices under test from thedevice under test storage cart into a test enclosure at the newlocation.
 16. The method defined in claim 15, wherein the test enclosurecomprises an electromagnetically shielded test enclosure and whereinloading the device under test into the test enclosure comprises loadingthe device under test into the electromagnetically shielded testenclosure.
 17. The method defined in claim 15 wherein the storage cartcomprises a plurality of shelves, the method further comprising: aftermoving the device under test storage cart to the new location, using atleast one sensor to assign a status to each shelf in the plurality ofshelves in the device under test storage cart.
 18. The method defined inclaim 15, further comprising: using the at least one computer-controlledrobotic arm, unloading the device under test from the test enclosure;and returning the device under test to the device under test storagecart.
 19. The method defined in claim 15, further comprising: using theat least one computer-controlled robotic arm, unloading the device undertest from the test enclosure; and loading the device under test intoanother device under test storage cart.
 20. The method defined in claim15, further comprising: in response to loading the device under testfrom the device under test storage cart into the test enclosure, testingwireless communications circuitry in the device under test.